What process describes the movement of molecules from areas of high concentration to low concentration?

What process describes the movement of molecules from areas of high concentration to low concentration?

• A. Diffusion
• B. Active Transport
• C. Facilitated Diffusion
• D. Endocytosis

Answer: (A)

The movement of molecules from areas of high concentration to low concentration is known as diffusion. This process occurs spontaneously and does not require energy input from the cell. Molecules naturally move along their concentration gradient, seeking to achieve an equilibrium where they are evenly distributed throughout a space. In biological contexts, diffusion is crucial for processes such as the exchange of gases in the lungs, where oxygen moves from areas of high concentration in the alveoli to areas of lower concentration in the blood. Similarly, it plays a role in nutrient absorption, cellular respiration, and the removal of waste products from cells. Other processes mentioned do not describe this movement. Active transport, for instance, involves the movement of molecules against their concentration gradient, which requires energy (often in the form of ATP). Facilitated diffusion also describes the movement of molecules down their concentration gradient but involves specific transport proteins to assist in the passage across the membrane, particularly for larger or charged molecules. Endocytosis is a process where cells engulf material, forming a vesicle to bring the substance into the cell, and is not solely dependent on concentration gradients.

The movement of molecules from areas of high concentration to low concentration is known as diffusion. This process occurs spontaneously and does not require energy input from the cell. Molecules naturally move along their concentration gradient, seeking to achieve an equilibrium where they are evenly distributed throughout a space.

In biological contexts, diffusion is crucial for processes such as the exchange of gases in the lungs, where oxygen moves from areas of high concentration in the alveoli to areas of lower concentration in the blood. Similarly, it plays a role in nutrient absorption, cellular respiration, and the removal of waste products from cells.

Other processes mentioned do not describe this movement. Active transport, for instance, involves the movement of molecules against their concentration gradient, which requires energy (often in the form of ATP). Facilitated diffusion also describes the movement of molecules down their concentration gradient but involves specific transport proteins to assist in the passage across the membrane, particularly for larger or charged molecules. Endocytosis is a process where cells engulf material, forming a vesicle to bring the substance into the cell, and is not solely dependent on concentration gradients.